Chapter 2

Chapter 2

1. Percentages and Conversions

   • perCENT - cent = 100, per = out of, percent= a measure out of 100
   • Fraction to Percentage - multiply the fraction by 100, then divide the numerator by the denominator to get the percentage
   • Percentage to decimal - copy the percentage and put the numbers AFTER the decimal point

2. Percentage Calculations

   • Percentage Increase - added a percentage to the original amount
   • Percentage Decrease - subtract a percentage to the original number
   • Percentage Manipulation
     • (100% +/- x) x amount or whats left.
     • Remember - WHAT IS LEFT?
       • When decreasing - find out what is left... e.g decrease by 60% = amount x 0.40
   • Percentage of an Amount - turn percentage into a decimal and times it by the amount

3. Financial Calculations

   • Cost Price - How much it cost to make the item
   • Mark Up - the amount added to cost price to make selling price
   • Selling Price - the final amount of what it is sold for at shops or markets
   • Discount - the amount subtracted from the selling price
   • Profit and Loss
     • Profit - When you gain something - if selling price is bigger than cost price
     • Loss - if Cost price is bigger than selling price
     • %Profit = profit/cost price x 100
     • %profit = profit as a pecentage
   • Commision - the payment to an employee = percentage sales make

4. Understanding Ratios

   • Ratios are two ro more numbers that compare but are of the same unit (km, cm, L, mL ect.)
     • Ratios are only written as whole numbers (like fractions) and dont include the unit since they are of the same kind
       • Simplify ratios like how you simplify fractions e.g 3:6 - 1:3
   • Dividing a Ratio by a number - turn the ratio into two different fractions you can make, times the number by the fractions then those numbers are the two numbers in the ratio, simplify if needed.

5. Understanding Rates

   • Rates are like ratios but compare something per something, the most common is speed.
   • speed = distance/time
   • the last unit is always 1, you can simplify if needed to get to 1
   • To get a rate from a sentence, make the units into one letter and add a slash in between the units
     • 6 miles per 2 hours - 3m/h